This invention relates to a headlamp for vehicles, having a saucer-shaped reflector with two focuses, and having a light source located at one focus, with an adjustable screen mounted on a stationary plate-like bracket between a lens and the reflector that can be adjusted by a remote-controlled adjusting device between, at least, positions that provide high-beam and low-beam light.
European patent document (EP 0 723 108 A1) discloses a headlamp for vehicles wherein a gas discharge lamp serves as a light source, an arc of which is positioned at an inner focus of an ellipsoidal reflector. An outer focus of the reflector, and an adjustable screen adjacent to the outer focus, are located between the reflector and a lens. The screen is mounted on a stationary, plate-like bracket, a main length of which extends crosswise with respect to an optical axis, and which is positioned below the optical axis. One or more adjusting devices serve to displace the screen into positions providing low-beam and high-beam light, and to reverse the screen for right-hand and left-hand drive. The adjusting device is positioned outside an optical system comprising the reflector, screen and lens, and a mounting location for the stationary plate-like bracket and for the adjusting device is not apparent from European patent document (EP 0 723 108 A1). The screen can be adjusted in a vertical guide of the bracket into its high-beam and low-beam positions, or it can be pivoted about a horizontal axis extending crosswise with respect to the optical axis. The screen can easily get tilted during vertical displacement in the guide. When the screen is pivoted about the horizontal axis, light beams illuminating an area directly in front of the vehicle can be shielded, and an unwanted dark zone thus occurs temporarily in front of the vehicle. The screen is reversed for right-hand and left-hand drive by being pivoted about an axis extending in a light-exit direction, in a vertical center plane of the reflector. For providing asymmetrical low-beam light, the screen has two screen edge sections at different levels. In the high-beam position, the adjustable screen is placed below an upper edge of the plate-like bracket. The upper edge of the bracket then serves as a screen edge for producing a light/dark limit for high-beam light.
German patent document (DE 38 06 658 A1) discloses a headlamp for vehicles wherein a support frame of a lens attached at a front edge of a reflector serves as a bracket for a screen. The screen can be pivoted into its high-beam and low-beam positions about a horizontal axis extending crosswise to an optical axis. An adjusting device of the screen is located on a back of the reflector and is formed by an electric stroke magnet (solenoid). The stroke magnet is hinged to a downward-pointing swivel arm of the screen via a long stroke rod extending below the reflector. Assembly of the adjusting device is time-consuming and complicated since it must be attached to the back of the reflector, and a free end of the stroke rod must be connected to the swivel arm of the screen; thus the adjusting device and the screen do not form a unit that can be pre-assembled. In addition, a size of the system including the reflector, the screen and the lens is rather large, since the adjusting device and the long stroke rod are positioned outside the system.
German patent document (DE 41 02 586 A1) discloses a headlamp for vehicles having an adjustable screen that creates a light/dark border of asymmetrical low-beam light and is continuously adjustable so that the light/dark border of the low-beam light beam can adapt to inclinations of a vehicle, particularly of a motorcycle. The screen cannot be changed for high-beam and low-beam light. A surface area of the adjustable screen is so large that it shields all stray light beams from the light source below its screen edge. An arm-shaped bracket for the adjustable screen and an electric adjusting device are attached to the reflector. The screen is mounted at an upwardly-facing end of the bracket so that it can pivot about an axis that coincides with an optical axis of the headlamp. The lower end of the bracket extends out of a system defined between the reflector, the screen, and the lens, where it supports the electric adjusting device.
It is an object of this invention to provide a headlamp for vehicles as described in the opening paragraph above, wherein the remote-controlled adjusting device need not result in any increase in structural dimensions of the headlamp, with an additional bracket for the remote-controlled adjusting device being unnecessary, and a shielding of all stray light beams from the light source below an edge of the adjustable screen is made possible.